A long-forgotten work by Paul Cézanne is expected to fetch up to £12.5m at an auction next month.

The watercolour, a study for the French post-impressionist's Card Players oil paintings, re-emerged last week in the home of a Texan art collector after disappearing from public view in 1953.

It depicts the gardener of the artist's estate in Aix-en-Provence and forms part of the series created in the 1890s. "[It] offers us a rare glimpse into [his] artistic process, showing us how he worked through the pose and positioning of the characters that would come to populate his greatest masterpieces," said Sharon Kim, director of impressionist and modern art at Christie's in New York.